In jet engine powered aircraft it is common practice to use hot compressor discharge air as the motive force for air motors which are used to operate various controls. It is not uncommon for the temperature of the compressor discharge air on entering an air motor to exceed 1100.degree. F. Unfortunately, the rotors and housing of the air motor conduct heat from the compressor discharge air into the bearings which support the rotors. Even though the bearings are heat treated, after a period of time, the heat which is transmitted through the shaft and housing can cause excessive wear of the races. Thereafter, the pressure required to operate the rotors increases and at some point in time the rotors can freeze and thereby render the controls which are operated thereby inoperative.